I am A Registered Nurse and wound specialist in a nursing home. I'm currently treating a wound quite like the one you described that was found on admission from a hospital. I have had excellent results in healing the wound which at the beginning measured 6.5cm x 6cm x 4cm deep with undermining and a 5cm tunnel. undermining is when the wound is open under the edges and a tunnel is when there is deep openings that are under the skin. treatment: first have your physician give you a prescription for collagenase santyl with several refills. This is a chemical that cleans the wound and aids in healing. supplies: bulb syringe (boil for 20min and reuse each time)4x4s, abdominal pad, normal saline (can be made by adding 1tsp salt to a quart of sterile water) tape and gloves. Put on gloves and fill the bulb syringe with saline and cleanse the wound thoroughly. use 1 4x4 to wipe out wound then reflush with saline and pat dry. apply collagenase santyl on a 4x4 starting in the center and circling out with about a 1/4 inch space between the line as you spiral out. Next place this 4x4 with the santyl directly on the wound making sure that the whole wound bed is covered. apply the abdominal pad over the 4x4 and tape into place. Change this dressing once a day or as needed if BM comes in contact. Make sure to turn him at least every 2 hours. I turn my resident every hour but that may not be possible for you. you should notice a difference within 1-2wks goodluck!